Drugs of Unit 3 in random order Flashcards
Disopyramide
Tx: Arrythmias (Class Ia)
Mech: Na channel blocker
- Even stronger antivagal effects (than quinidine)
SE:
- Antimuscarinic effects (opposite of DUMBBELS)
- Wouldn’t use w/ glaucoma pts
Sotalol
Tx: arrytmhias (Class III)
Mech: K+ channel blocker
Also a beta blocker
Heparin
Tx: Anticoagulant
Mech: Heparin binds to anti-thrombin (protease inhib) and increases its affinity for clotting factors by 1000x
Low doses: inhibits Xa, decreasing formation of thrombin
High doses: inhibits thrombin and irreversibly binds to IXa, XIa, and XIIa
Heparin inhibits clotting in vivo and in vitro
Activates lipoprotein lipases in blood
Where we get it: located in mast cells
Harvest it from cow lung and pig intestines
Strong neg charge
Not synthetic-each batch tested individually
Pharmacokinetics: IV or subQ
Too large to be absorbed in GI tract or pass placenta
Not risk free in pregnancy though
Immediate onset–T1/2=1 hour
Degradation via heparinase
Can bind to variety of proteins so dose response in unpredictable
_Toxicity: _
- Generally non toxic
- Major danger is bleeding
- Overdose treated w/ protamine sulfate
- Strong pos charge binds w/ strong neg of heparin
- Long term use can lead to
- Osteoporosis-act. osteoclasts
- Thrombocytopenia-loss of platelets
- HIT-heparin induced thrombocytopenia
- Hypersensitivity-rare but we are injecting animal products
Isosorbide dinitrate
Tx: Angina
Slow release nitrate formulation
Can be given orally
Slow enough that effects occur before 1st pass metabolism
“-afils”
Sildenafil
Vardenafil
Tadalafil
Avanafil
Tx: ED
Mech:
- Inhibits type 5 cGMP phosphodiesterase
- Nitrates→NO→cGMP→smooth m relax
- cGMP degraded to 5’GMP via type 5 cGMP phosphodiesterase
- Relaxes arteries in corpus cavernosum→increase BF
SE:
- Slight drop in BP
- Do not use w/ alpha 1 blockers or nitrates
- Too much drop in BP
- Stroke
- MI (may be due to activity)
- Visual disturbances
- Impaired blue/green color discrimination
- NAION-some potential for damage to retina induced by cGMP PDE inhibitors
Metabolism: P450
Calcium chelators
Citric acid (in blood transfusion bags(
ADTA
EGTA
Tx: Anticoagulants
Mech: Chelate Ca
Remove Ca from clotting cascade (4 steps need Ca)
We don’t give these to people b/c Ca is involed w/ lots of mechanisms
Fondaparinux
Tx: Anticoagulant
Synthetic heparin like drug
T1/2=17 hrs
Acts only on Xa
Can cross placenta
Can’t bind protamine
Given SubQ
Warfarin
Tx: Anticoagulant
Mech:
- Vit K analog–*Koagulation*
- Inhibits enzyme that allows vit K to be recycled
- Leads to vit K deficiency
- Vit K is essential for factors 7, 9, 10 and prothrombin
- Works indirectly-doesn’t directly block clotting cascade
Route: Oral
Pharmacokinetics:
- Factor T1/2s (hrs)
- VII–6
- IX–24
- X–40
- II–60
- So 5-6 T1/2s for 99% to be gone
- 30-36 hrs
- So initial onset is 24+ hours
- Metabolism
- P450
- Lots of drug interactions
- Phenytoin/barbituates vs grapefruit juice, etc.
- Diet interactions
- Lots of Vit K in green veggies
Toxicity:
- Overdose-tx w/ Vit K
- Hemorrhage
- Can pass placenta-preg. category X
“-kinase”s
Streptokinase
Urokinase
Tx: Thrombolytic agent
(dissolve formed clots)
Mech:
- Urine plasminogen activator=Enzyme activator
- Plasminogen→plasmin
- Plasmin:
- hydrolyzes fibrin
- degrades fibrinogen
- degrades factors V and VII
Route: IV
SE: May prolong bleeding time
Deferoxamine
Tx: Acute iron OD
Mech: Iron chelator
De-Fer-oxamine
_De_toxes _Fer_rous overdose
Esmolol
Tx: arrythmias (Class II)
Mech: B1 blocker
More rapid onset of action
SE:
- Bradycardia
- Hypotension
- B2 effects-asthma
Adenosine
Tx:
- Arrythmias (Other class)
- Atrial Tachycardia
Mech:
- Binds to adenosine receptor
- Decreases firing rate of AV node
- Coronary vasodilator
Kinetics-Very short T1/2=10sec
Eptifibatide
Tx: Anticoagulant
Mech: Platelet inhibitor
Fibrinogen receptor blocker on platelet (GPIIB/IIIA receptor)
Clinical use: Decrease white thrombi
Used for coronary operation
Route: IV
SE: Thromobocytopenia
Gemfibrozil
Tx: Hyperlipidemia
Mech: Bind to PPAR-peroxisome proliferation acting receptor
Effects
- Increase transcription of LPLase
- Decrease VLDL
- Decrease Trig.
SE:
- GI upset-nausea, vomiting
- Can displace warfarin from plasma binding sites
“Choles- or coles-“
Cholestyramine
Colestipol
Coleselevam
Tx: Hyperlipidemia
Mech: Irreversibly binds bile acids in gut→choles. excreted
Effects:
- Decrease circulating cholesterol
- Increase LDL receptor
Combine w/ statins for additional decrease in LPs
SE:
- No systemic SE-too big to be absorbed
- Can bind drugs
- Digoxin
- Oral anti-coagulants
- Decrease absorption of fat soluble vitamins
- GI upset-nausea
Tissue plasminogen activator (TPA)
Tx: Thrombolytic agent
(dissolve formed clots)
Mech:
- Urine plasminogen activator=Enzyme activator
- Plasminogen→plasmin
- Plasmin:
- hydrolyzes fibrin
- degrades fibrinogen
- degrades factors V and VII
Route: IV
SE: May prolong bleeding time
Diltiazem
Tx: Arrythmias except vent. arrythmias (class IV)
Mech: Ca channel blockers
Increase refractory period
Lidocaine
Tx: arrythmias (Class Ib)
*also LA
Mech: Na channel blocker
Route: Given IV
Kinetics: First pass effect
Toxicity: Low
SE:
- Less likely to cause arrythmias but can enter CNS
- Tremors
- Seizures
Argatroban
Tx: Anticoagulant
Peptide from hirudin-diff structure, similar mech
Clinical use: when patient has HIT
Skin grafts and reattaching body parts
Route: Injection
Alprostadil
Tx: ED
Injectable prostaglandin (PGE1) leads to vasodilation when injected directly into penis
Mipomersen
Tx: hyperlipidemia
Antisense oligonucleotide
Mech: Binds to mRNA of ApoB
Prevents Apo from being synth
*(Apolipoprotein)*+cholesterol→VLDL
Must be given by injection
Ticlopidine
Tx: Anticoagulant
Mech: Platelet inhibitor
ADP receptor blocker on platelet
SE:
- Neutropenia-loss of neutrophils
- Agranulocytosis
Dabigatran
Tx: Anticoagulant
Mech: Direct thrombin inhibitor
Enzyme inhibitor
Route: Oral
Kinetics:
- Prodrug
- Onset w/in 1 hr
- P450 inhibitor may impact
SE-hemorhhage
Glyceryl Trinitrate (nitroglycerin) (GTN)
Tx: Angina
Mech:
GTN→NO→Act. guanylate cyclase→cGMP→vasodilation
Rapidly dilates all blood vessels, including coronary art.
Route: Given sublingually–1st pass effect
Effects last 30-60min
Rapid tolerance so cannot take continuously
SE:
- Hypotension
- Skin flushing
- Headache-opening blood vessels in brain, feel pulsing
*Nitroglycerin is unstable and explosive in some conditions